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punched card

The punch card is the oldest form of data carrier for the storage as well as the input and output of data. It dates from 1890 and was invented by the American inventor Herman Hollerith (1860 to 1929), hence the name Hollerith punch card.

The punch card is a cardboard divided into columns and rows. The data is punched through holes according to a fixed code and can be scanned mechanically, optically or electrically.

The punched card has a standardized format measuring 187.3 mm x 82.5 mm and a thickness of 0.178 mm.

Standardized punch card, photo: Uni-Saarland

Standardized punch card, photo: Uni-Saarland

Rectangular holes were punched inthematrix consisting of twelve rows and 80 columns; a total of 80 characters could be stored. The 12 rows are divided into the upper two, called the over-hole zone, and the lower ten, called the normal hole zone. The characters are represented by combinations of holes: Numerals by one hole, letters and special characters by two or three holes using the over-hole zone, with one column always representing one character. Thecharacter set used was the punch card code of the IBM company.

Englisch: punched card
Updated at: 11.09.2009
#Words: 174
Links: data, carrier, name, code,
Translations: DE

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